Whilist messing around with the Pokedex 3D, I found another way to crash the 3DS.
1.Go to an area with no internet connection.
2.Press ¨Update¨ on the Pokedex 3D.
3. It‛ll start to connect. When it does try, after 5 secs, press home.
4. It'll freeze. press the power button. then when it pops up the power off screen, press home
and its stuck on home.
I don't know if its usefull...

Generally speaking, for a crash to be useful, it has to be caused by some data that you can manipulate

For example a character name, which you have some method of editing other than through the game (i.e. decrypting and modifying save game manually). That way you are able to control the data that is used to crash the system and through that use the "right" data to gain control of the system.

In a case where you can't control any data being accessed at the time of the crash (such as what you said), it is useless, because you can't manipulate memory to gain control.